For liquid-crystal projectors and projectors that generate image light using a DMD (digital micromirror device) and project the image light via a projection lens, lens covers that cover a projection lens are used in order to protect the projection lens when no projection is performed.
Examples of the lens covers include those having the shape of a cap, which are attached to the projection lens, and sliding-type ones in which a part of a chassis of the projector slides and covers the projection lens.
Although those that have the shape of a cap may be lost, the sliding covers will not be lost because they are integrated with the chasses of the projectors.
Examples of the sliding covers include one disclosed in Patent Literature 1 (JP2-44729U) and Patent Literature 2 (JP2008-102376A).
The one disclosed in Patent Literature 1 is a lens cover that is only manually slidable.
A lens cover that is only manually slidable, like the one in Patent Literature 1, may stop between a fully-open state and a fully-closed state, and thus, an operator needs to operate the lens cover in such a way that it is moved to the fully open state or to the fully closed state, because of lens cover may stop in the intermediate state, and such operation is troublesome.
The lens cover disclosed in Patent Literature 2 has been made in view of the problem arising in the above technique disclosed in Patent Literature 1, and is provided with a biasing means for biasing a lens cover to move to a full open state or to a fully closed date.